riod 19902015 copper production increased 40 from 194 Mt in 1990 to 2 73 Mt in 2015 Hence the CO 2 intensity of copper production reduced signifcantly from 267 t CO 2 t copper in 1990 to 162 t CO 2 t copper in 2015 or a reduction of 40 These shifts can be e xplained by important efciency gains in copper production 60 reduction in energy use per tonne of copper since 1990 131 in particular the shift to fashsmelting This process requires a lot of o xygen and hence higher levels of electricity use for the production of o xygen which e xplains the increase in indirect emissions Further efciency gains came from new and modernised furnaces renovated electrical equipment efcient drying technologies residu al heat recovery systems and energy management systems 132 54 Zinc Nearly all mineral zinc concentrates processed in the primary zinc refning process are sul phides which also usually contain other metals such as lead copper nick el iron cadmium and other precious and rare metals such as silver gold indium cobalt and germanium The most commonly occurring ores are sphalerite also known as zinc blende ZnS and another variety of sphalerite called marmatite which contains signifcant quantities of iron sulfdes There are two main processes the electrolytic process and the thermal process Over 90 of the world s production comes from the electrolytic process The electrolytic process has four stages concentration of the ore at the mining site roasting of the ore with air conversion of zinc o xide to zinc sulfate electrolysis of zinc sulfate solution The ore is mined crushed ballmilled and then concentrated by froth foatation This re moves unwanted components including lead compounds and waste rock 133 Primary zinc is produced from zinc mineral concentrates via either the RLE R oasting L eaching Electrolysis or the ISF Imperial Smelting Furnace route In the RLE route calcine ZnO is produced from zinc concentrates in a roasting process and a zinc sulphate solution ZnSO4 obtained following a leaching and purifcation step Some 131 European Copper Institute 132 Ibidem 133 Several new methods have now been developed that dispense with the roasting stage obtaining zinc sulfate directly from concentrated zinc sulfde ore They generally use much more e xtreme conditions and are suitable for lowergrade ores One process developed in Canada and capable of recovering 99 of the zinc in the ore uses pressures in e x cess of 10 atmospheres and a temperature ofca150C The presence of iron in the ore concentrate is important in this method as it is in part responsible for the conversion of zinc sulfde to zinc sulfate V ery high zinc e xtraction rates up to 99 from lowgrade ores as low as only 5 zinc can also be achieved using bacterial action The bacteria used thrive at temperatures up toca45C and produce weak zinc solutions that are concentrated for electrolysis using solvent e xtraction CIES ND The recycling of copper is the most comprehensive among the nonferrous metals Copper metal scrap can be in the form of copper scrap such as fabrication rejects wire scrap plumbing scrap apparatus elec trical systems or products from cable processing alloy scrap such as brass gunmetal bronze in the form of radiators fttings machine parts turnings or shredder metals copperiron scrap lik e electric motors or parts thereof plated scrap circuit elements and switchboard units telephone scrap transformers and shredder materials Another large group of coppercontaining materials is composed of o xidised materials including drosses ashes slags scales ball mill fnes catalysts as well as materials resulting from pollution control systems The copper content of secondary materials varies from 1 to nearly 100 The associated metals that are recovered are mainly zinc lead tin iron nick el and aluminium as well as precious metals 130 Figure 26 Evolution of direct and indirect emissions from copper production in the EU 28 Mt C O 2 eq Source European Copper Institute European copper production is heterogeneous and diferent companies have diferent lev els of vertical integration composition of raw materials and processes to e xtract and refne all the valuable elements by primary and secondary smelting routes Between 1990 and 2015 the emissions from copper production in the EU decreased 15 Direct emissions fell 40 but indirect emissions went up 25 However over the same pe 130 JRC 2017a 2015 2005 1990 3 7 10 6 3222 5203 1981 2664 4 771 2493 4439 2 107 1946 15 Indirect Emissions Mt CO eq Direct Emissions Mt CO eq MET ALS IN A CLIMA TE NEUTRAL EUROPE A 2050 BL UEPRINT 45